javascript find substring in string and replace code example

Example 1: javascript replace string

var str = "JavaScript replace method test";
var res = str.replace("test", "success");  
//res = Javscript replace method success

Example 2: replace all occurrences of a string in javascript

const p = 'dog dog cat rat';

const regex = /dog/gi;

console.log(p.replace(regex, 'cow'));
//if pattern is regular expression all matches will be replaced
//output: "cow cow cat rat"

Example 3: how to use the replace method in javascript

let string = 'soandso, my name is soandso';

let replaced = string.replace(/soandso/gi, 'Dylan');

console.log(replaced); //Dylan, my name is Dylan